7-(3-Substituted ureido and -thioureido) cephalosporins

ABSTRACT

Cephalosporin compounds with 3-substituted ureido or -thioureido group at position 7 and hydrogen or heterocyclicthiomethyl groups at position 3 are prepared. These compounds are antibacterial agents.

United States Patent Crooij et al.

7-(3-SUBSTITUTED UREIDO AND -THIOUREIDO) CEPHALOSPORINS Inventors: Pierre Crooij, Genval; Alain Colinet,

La Hulpe, both of Belgium Assignee: Recherche et Industrie Therapeutiques, Belgium Filed: May 17, 1973 Appl. No.: 361,393

Related US. Application Data Continuation-impart of Ser. No. 265,371, June 22, i972, abandoned.

US. Cl. 260/243 C; 424/246 Int. Cl. C07D 501/24 Field of Search 260/243 C Primary Examiner-Nicholas S. Rizzo Attorney, Agent, or FirmAlan D. Lourie; William H. Edgerton [57] ABSTRACT Cephalosporin compounds with 3-substituted ureido or -thioureido group at position 7 and hydrogen or heterocyclicthiomethyl groups at position 3 are prepared. These compounds are antibacterial agents.

6 Claims, N0 Drawings 1. 7-(3-SUBSTITUTED UREIDO AND -THIOUREIDO) CEPHALOSPORINS This application is a continuation-in-part of copending application Ser. No. 265,37l,'filed June 22, 1972, now abandoned.

This invention relates to new chemical compounds known as cephalosporins, which compounds possess antibacterial activity.

The compounds of this invention are represented by the following structural formula I:

S R-NH-ZNH- l I, N cH, R o (Formula I) COOM wherein R is either saturated or unsaturated aliphatic group of up to 6 carbon atoms with straight or branched chain, unsubstituted or substituted with from one to two groups selected from the group consisting of halogen, hydroxy, methoxy, azido, amino, carboxy, cyano, nitro, diloweralkylamino (each alkyl containing from one to four carbon atoms), aryl, saturated or unsaturated cycloalkyl of up to 6 carbon atoms and 5 or 6 membered heterocyclic ring containing one to four two groups selected from the group consisting of halogen, hydroxy, cyano, nitro, aceatmido, sulfamoyl, mercapto, methylthio, lower alkyl, lower alkoxy and diloweralkylamino (each alkyl or alkoxy containing from one to four carbon atoms); aryl, saturated or unsaturated cycloalkyl of up to 6 carbon atoms or 5 or 6 membered heterocyclic ring containing one to four atoms of N, O or S, said aryl, cycloalkyl or heterocyclic ring being unsubstituted or substituted with one or two groups selected from the group consisting of halogen, hydroxy, cyano, nitro, acetamido, sulfamoyl, mercapto, methylthio, lower alkyl, lower alkoxy and diloweralkylamino (each alkyl or alkoxy containing from one to four carbon atoms);

Z is O or S;

R is hydrogen, pyridinium, N-piperidino -or N- piperazinodithiocarboxylate or S-l-Iet wherein Het is a 5 or 6 membered heterocyclic ring containing one or more atoms of N, O or S, with or without ring substituents such as halogen, lower alkyl, lower alkoxy, amino, lower alkylamino or dialkylamino, each alkyl or alkoxy containing from I to 4 carbon atoms; and

M is hydrogen, alkali metal cation, alkaline earth cation, or a non toxic organic ammonium cation. Examples of 5 or 6 membered heterocyclic rings containing one or more atoms of N, O or S, with or without ring substituents as indicated hereinabove are ii -U s-u i/ KNJMR3 \Y N L l W Kl" wherein R is hydrogen, halogen, lower alkyl, lower alkoxy, nitro, acetamido, sulfamoyl, amino, lower alkylamino or dialkylamino, each alkyl or alkoxy containing from 1 to 4 carbon atoms.

The preferred compounds are those wherein R is unsubstituted or substituted aliphatic group of up to 6 carbon atoms and wherein R is S-Het wherein Het is l,3,4-thiadiazol-2-yl, 1,3,4-triazol- 2-yl, 1,2,3-triazol--yl, 1,2,4-triazol-3-yl, 1,2,4- oxadiazol-3(5)-yl, 1,3,4-oxadiazol-2-yl, 1,2,4- thiadiazol-3(5)-yl, tetrazol-S-yl, pyridyl, pyrimidyl, pyrazinyl or 2-thiazolin-2-yl, all of which may be unsubstituted or substituted with one or more of the substituents which were enumerated above. Particularly preferred are the lower alkyl (1-4 carbon atoms) substituted S-membered heterocyclic compounds, that is, 5-alkyl-l,3,4-thiadiazol-2-yl, 5( 3 )-alkyl-l ,2,4-oxadiazol-3(5 )-yl, 5-alkyl-1,3,4- oxadiazol-2-yl, l-alkyl-l,2,3-triazol-5-yl, l-alkyl- 1,2,4-triazol-3-yl, 5-alkyl-l,2,4-triazol-3-yl, 5- alkyl-l ,3,4-triazol-2-yl, 1,5-dialkyl-l ,2,4-triazol- 3-yl and l-alkyl-tetrazol-S-yl.

The compounds of this invention are prepared by a series of reactions, the essential reactions being first 1. either catalytic hydrogenation of the 3-acetoxy group to yield the 3-methyl group or displacement of the 3-acetoxy group of 7-aminocephalosporanic acid (7-ACA) with the desired mercaptoheterocyclic compound to give the 3-heterocyclicthiomethyl-substituted compound and then reaction of the 7-amino group of 7-ACA with the appropriate isocyanate or isothiocyanate or 2. reaction of 7-ACA with phosgene (or thiophosgene) to yield isocyanato (or isothiocyanato) cephalosporanic acid which is reacted with the appropriate amine of formula RNH and then either catalytic hydrogenation of the 3-acetoxy group to yield the 3-methyl group or displacement of the 3- acetoxy group of 7-ACA with the desired mercaptoheterocyclic compound.

Alternatively, the products of formula 1 are also obtained by reaction between the substituted carbamoyl or thiocarbamoyl halide, preferably chloride, and the 3-substituted-7-amino-3-cephem-4-carboxylic acid in a non reactive solvent, the starting carbamoyl or thiocarbamoyl halide being prepared from phosgen or thiophosgen and the adequately substituted amine in a non reactive solvent.

The catalytic hydrogenation is carried out in aqueous solution, preferably with a palladium catalyst on an inert carried such as carbon or baryum sulfate, the starting 7-aminocephalosporanic acid being reacted in the form of a soluble salt, preferably an alkali metal salt as sodium salt.

The displacement reaction is carried out at neutral pH in a non reactive polar solvent such as water, tetrahydrofuran, acetone or a water-acetone solvent system at a temperature comprised between 40 and 80C until the reaction is completed as indicated by the disappearance of the acetoxy carbonyl band in the infra-red absorption spectrum.

. The treatment with the isocyanate is carried out in a tertiary amine -for instance, pyridineor in a mixture The order. of'the displacement reaction and the isocyanate treatment may be reversed.

When R is substituted by hydrox'y,-mercapto, amino or carboxy, the corresponding reactant must obviously be adequately protected according to any method known from the art for, such protection.

According to another embodiment of the present invention, the compounds of formula 1 wherein R is amino-substituted are also obtained by selective catalytic hydrogenation of the corresponding azido substituted cephalosporin.

As indicated above, also included with the scope of this invention are the nontoxic alkali metal, alkaline earth or organic ammonium salts of formula I, all of which have antibacterial activity. These may be isolated directly from the final reaction or can be prepared from the free acid by reaction with the appropriate base.

The starting material for preparing the products of this invention are either known or readily preparable by known methods or described therein.

The products of this invention are antibacterial agents active against Gram-negative and Gram-positive organisms such as Staph. aureus including macrolides resistant Staph. aureus strains, Aerobacter aerogenes, Klebsiella pneurrioniae, Salmonella paratyphi, Shigella sonnei, Proteus mirabilis, Proteus morganii and Candida albicans and particularly active against Staph. aureus, E. 'coli and Kle bsiella pneumoniae.

For the preferred compounds of this invention as indicated above, the minimum inhibitory concentrations in the conventional agar-inclusion test are less than 2 microgram/ml. for certain Staphylococcus and less than 10 microgram/ml. for certain E. coli and Klebsiella pneumoniae strains.

The products of this invention may be administered by parenteral or oral route, being therefore formulated into adequate compositions in the same manner d other cephalosporin H) The dose that is administered to the subject will depend on the severity and type of infection as well as the general condition of the subject.

Among the preferred compounds of the invention are:

Group I compounds:

7-( 3-n-propylureido)-3-( 1,3,4-oxadiazol-2- ylthiomethyl)-3-cephem-4-carboxylic acid (compound RIT no. 3024) 7-(3-n-propylureido)-3-(5-methyl-1,3,4-oxadiazol-2- ylthiomethyl)-3-cephem-4-carboxylic acid (compound RIT no. 3008) v Group II compounds:

, of a tertiary am ne. with a non reactive organ c solvent. g for example,triethylamine andmethylene'chlorideat a'tem erature inferior to I 'Grou III 7-[3-(2-chloro-ethylureido)1-3-(5-methyll ,3 ,4-

thiadiazol-2-ylthiomethyl)-3-cephem-4-carboxylic acid (compound RIT no. 2892) 7-[ 3-( 2-chloro-ethylureido)]-3-(5-methyll ,3,4-

.oxadiazol-2-ylthiomethyl)-3-cephem-4-carboxylic acid (compound RIT no. 3007) 7-[3-(2-chloro-ethylureido)]-3-(1,3,4-triazol-2- ylthiomethyl)-3-cephem-4-carboxylic acid (compound RIT no. 321-1) 7-[3-( 2-chloro-ethylureido)]-3-(pyrimidin-2- ylthiomethyl)-3-cephem-4-carboxylic acid (compound RIT no. 3055) 7-[ 3-(2-chloro-ethylureido)]-3-( 1 -methyl- 1H- tetra zol 5-ylthiornethyl) 3-cephem-4-carboxylic acid (compound RIT no.'32l9) 7-(3-allylureido)-3-5-methyl-1,3,4-thiadiazol-2- ylthiomethyl)-3-cephem-4-carboxylic acid (compound RIT no. 2746) I 7-( 3-allylureido)-3-(S-methyl-l ,3,4-oxadiazol-2- ylthiomethyl)-3-cephem-4-carboxylic acid (compound RIT no. 3011) 7.-( 3-allylureido)-3-( S-methyl-l ,3 ,4-triazol-2- ylthiomethyl)-3-cephem-4-carboxylic acid (compound RIT no. 3013) 7-(3-allylureido)-3-(2-thiazolin-2-ylthiomethyl)-3- cephemA-carboxylic acid (compound RIT no. 2747) I 7-( 3-allylureido )-3-( 1 -methyl-1 H-tetrazol-S- ylthiomethyl)-3-cephem-4-carboxylic acid (compound RIT no. 3241) Group IV compounds:

7-( 3-benzylureido)-3-( S-methyl- 1 ,3 ,4-thiadiazol-2- ylthiomethyl)-3-cephem-4-carboxylic acid (compound RIT no. 2912) 7-(3-benzylureido)-3-(1,3,4-triazol-2-ylthiomethyl)- 3-cephem-4-carboxylic acid (compound RIT no. 3212) 7-(3-benzylureido)-3-(pyrimidin-Z-ylthiomethyl)-3- cephem-4-carboxylic acid (compound RIT no. 3056) 7-( 3-benzylureido)-3-( l-methyll H-tetrazol-S- ylthiomethyl)-3-cephem-4-carboxylic acid (compound RIT no. 3220) Group V compounds:

7-(3-p-chlorobenzylureido)-3-(S-methyl-1 ,3,4-

thiadiazol-2-ylthiomethyl )-3-cephem-4-carboxylic acid (compound RIT no. 3210) Group VI compounds:

7-(3-a-methylbenzylureido)-3-(5-methyl-1 ,3 ,4-

7(3-a-methylbenzylureido)-3-(5-methyl-l,3,4-

oxadiazol-Z-ylthiomethyl )-3-cephem-4-carboxylic acid (compound RIT no. 3217) 7-(3-a-methylbenzylureido)-3-( l-methyl-lH- tetrazol-S-ylthiomethyl)-3-cephem-4-carboxylic acid (compound RIT no. 3242) As resulting from the following Tables I to V1, the

above compounds of the invention are advantageous over the corresponding 3-acetoxymethyl compounds, i.e.:

7-(3-n-propylureido)cephalosporanic acid (compound RIT no. 3266) corresponding to the above Group I compounds 7-[3-(2-chloro-ethylureido)]cephalosporanic acid (compound RIT no. 3267) corresponding to the above Group II compounds 7-(3-allylureido)cephalosporanic acid (compound RIT no. 2758) corresponding to the above Group III compounds 7-(3-benzylureido)cephalosporanic acid (compound RIT no. 3265) corresponding to the above Group IV compounds 7-(3-p-chlorobenzylureido)cephalosporanic acid (compound RIT no. 3209) corresponding to the above Group V compounds 7-(3-a-methylbenzylureido)cephalosporanic acid (compound RIT no. 3208) corresponding to the above Group VI compounds The following Tables I to VI summarize the results of an in vivo mouse protection study in which a test compound is administered in graded dilutions to mice either subcutaneously in water or orally in a suitable suspending agent one hour after intravenous infection with uniformly lethal doses of S. aureus. The animals thiadiazol-Z-ylthiomethyl)-3-cephem-4-carboxylic are observed for 3 days. The total dose required to proacid (compound RIT no. 3203) tect percent of the infected mice is designated as the 7-(3-a-methylbenzylureido)-3-(1,3,4-oxadiazol-2- ED the most potent compounds having the lowest ylthiomethyl)-3-cephem-4-carboxylic acid (com- ED s (the indicated results give the evolution of the pound RIT no. 3213) ED with time):

TABLE I ED of the Group I compounds Hours after Hours after subcutaneous oral Compounds administration administration 3024 16 20 20 20 43 4s 57 so 3008 12 17 20 20 20 46 74 80 80 80 3266 7 20 20 20 20 57 80 80 80 80 TABLE II ED of the Group II compounds Hours after Hours after subcutaneous oral Compounds administration administration TABLE III ED of the Group III compounds Hours after Hours after subcutaneous oral Compounds administration administration 2746 14 17 20 20 40 40 40 40 3011 12 20 20 20 20 35 80 80 80 80 30l3 ll 16 20 20 20 20 46 61 80 80 80 80 2747 7 11 20 20 36 36 55 80 3241 11 20 20 20 20 39 73 80 80 80 2758 l4 19 20 20 20 20 56 63 80 80 80 80 TABLE IV ED of the Group IV compounds Hours after Hours after subcutaneous oral Compounds administration administration TABLE V ED of the Group V compounds Hours after Hours after subcutaneous oral Compounds administration administration TABLE VI ED of the Group VI compounds Hours after Hours after subcutaneous oral Compounds administration administration EXAMPLE 1 To a cooled suspension of 7-ACA 13.6 g) in distilled water (50 ml) are added by small fractions 89 ml of N NaHCO in water and 50 ml of acetone. To the solution are added a mixture of 16 m1 of 0.2 M NaH PO in water and 84 ml. of 0.2 M Na HPO in water (pH of the mixture 7.4) and a mixture of 5-mercapto-2-methyl- 1,3,4-thiadiazole (10.6 g, 80 mmol) in acetone ml) and N NaHCO' in water (60 ml). The flask which contained the 5-mercapto-2-methyl-l,3,4-thiadiazole is rinsed out with a mixture of water 10 ml), acetone (10 ml) and N NaHCO in water (10 ml) (pH of the mixture 6.8) which is added to the reaction medium which is then heated on an oil bath (C) to gentle reflux with stirring for 3 hours. After that reaction period, the pH of the medium is 7. The flask is placed in an ice bath and, when the temperature of the medium reaches 10C, the solution is slowly acidified with 12 N HCl (17 ml) to pH 3.9, the temperature being then 2C.

The precipitate is filtered, washed with 3 portions (10ml) of water, 3 portions ml) of acetone and 3 portions (50 ml) of ethyl ether.

The dried crude product (11.8 g) is suspended in water ml) and concentrated aqueous ammonium hydroxide (3.44 ml) is added slowly with vigorous stirring to reach complete solution at pH 7.00 under pl-I stat control. Charcoal (10 g) and, 10 minutes later, Dicalite SH (10 g) (an infusorial earth filter aid sold by DICALITE EUROPE NORD, Brussels, Belgium) is then added thereto. After 15 minutes standing, the mixture is filtered and the adsorbent is washed with water 20 ml) and 1/1. water-acetone 40 ml). The solution (pH 6.7) is acidified over a one hour period with 12 N HCl to pH 3.9. Acetone (80 ml) is added to facilitate the filtration. The precipitate is filtered, washed with water, acetone and ether to yield 7-amino-3-(2-methyl- 1 ,3,4-thiadiazol--ylthiomethyl)-3-cephem-4- carboxylic acid (8.27 g).

EXAMPLE 2 To a 6.888 g. aliquot of 7-amino-3-(2-methyl-1,3,4- thiadiazol-S-ylthiomethyl)-3-cephem-4-carboxylic acid in a one litre reaction flask are added methylene chloride (500 ml), triethylamine (5.6 ml) and methylisocyanate (3.5 ml). The mixture is stirred at room temperature for 18 hrs. The solvent is then removed by evaporation under reduced pressure and the residue is taken up in acetic acid (20 ml) and ethyl acetate (250 ml).

After filtration, ethyl ether is added to precipitate 7- (3-methylureido)-3-(2-methyl-1 ,3,4-thiadiazol-5- ylthiomethyl)-3-cephem-4-carboxylic acid (5.168 g).

R 0.10 (i 0.10) in the system methylisobutylketone/methanol/formic acid 60/6/2, detection with bromcresol green and KMnO nmr: 2.58 s (3H), 2.66 s (3H), 3.37 d (1H)(J l4 c./sec.), 3.74 d (1H)(J 14 c./sec.), 4.18 d (1H)(J 18 c./sec.), 4.52 d (1H)(J 18 c./sec.), 5.00 d (1H)(J 4.7 c./sec.), 5.60 d (1H)(J 4.7 c./sec.).

EXAMPLE 3 7-ACA (13.65 g) and 2-thiazoline-2-thiol (11.92 g) are suspended in 500 ml. of phosphate buffer 0.2 M (Na HPO /NaH PO pH 6.5. To the suspension are added with stirring 12.6 g. of NaHCO and 250 m1. of acetone. The reaction medium is heated for 2% hrs with stirring on a 80C water bath. The solution is then treated with charcoal, cooled (5l0C) and acidified to pH 4 with 2 N hydrochloric acid. The obtained suspension is diluted with acetone and stirred for 20 minutes. The precipitate is filtered, washed with water, acetone and ethyl ether and dried under reduced pressure to yield 7-amino-3-(2-thiazolin-2-ylthiomethyl)-3- cephem-4-carboxylic acid.

EXAMPLE 4 In a one litre reaction flask and to a 6.528g. aliquot of 7-amino-3-(2-thiazolin-Z-ylthiomethyl)-3-cephem- 4-carboxylic acid prepared according to the procedure described in Example 3 are added methylene chloride (500 ml), tributylamine (9.5 ml) and methylisocyanate (3.5 ml). The mixture is stirred at room temperature for 15 hrs and then at 50C for 6 hrs. The solvent is then removed by evaporation under reduced pressure and the residue is taken up in acetic acid ml) and ethyl acetate (250 ml).

After filtration, ethyl ether is added to precipitate 7- (3-methylureido)-3-(2-thiazolin-2-ylthiomethyl)-3- cephem-4-carboxylic acid.

R;= 0.09 (i 0.10) in the system methylisobutylketone/methanol/formic acid 60/6/2, detection with bromcresol green and KMnO nmr: 2.60 s (3H), 3.03 m (2H 2H), 3.32 d (1H)(J 13 c./sec.), 3.67 d (1H)(J 13 c./sec.), 4.01 d (1H)(J 15 c./sec.), 4.39 d (1H) (J 15 c./sec.), 5.00 d (1H) (J 5 c./sec.), 5.60 d (1H) (.1 5 c./sec.).

EXAMPLE 5 In a one litre reaction flask and to 5.360 g. of 7- amino-3-desacetoxy-cephalosporanic acid (7-ADCA) are added ethylisocyanate (2.16 ml) and pyridine (500 ml). The mixture is stirred at room temperature for 24 hrs. The unreacted 7-ADCA is separated by filtration. The solvent is removed by evaporation under reduced pressure, the residue is taken up in petroleum ether and 7-(3-ethylureido)-3-desacetoxy-cehpalosporanic acid, pyridinium salt is separated by filtration.

R,= 0.34 (i 0.10) in the system methylisobutylketone/methanol/formic acid /6/2, detection with bromcresol green and KMnO nmr: 1.00 t (3H) (J 6.6 c./sec.), 2.02 s (3H), 3.00 q (2H) (J 6.6 c./sec.), 3.28 d (1H) J 17 c./sec.), 3.69 d (1H) (J 17 c./sec.), 5.05 d (1H) (J 5 c./sec.), 5.65 d (1H) (J 5 c./sec.), pyridinium 7.55 m (2H), 7.90 m (1H), 8.65 m (2H).

EXAMPLE 6 In a one litre reaction flask and to a 6.888 g. aliquot of 7-amino-3-( 2-methyl-l ,3,4-thiadiazol-5- ylthiomethyl)-3-cephem-4-carboxylic acid prepared according to the procedure described in Example I, are added pyridine (500 ml) and ethylisocyanate (2.4 ml). The mixture is heated to 50C and stirred for 3 hrs at that temperature. The solvent is then removed by evaporation under reduced pressure and the residue is taken up in acetic acid (20 ml) and ethyl acetate (250 ml).

After filtration, ethyl ether is added to precipitate 7- (3-ethylureido)-3-(2-methyl-1,3,4-thiadiaz0l-5- ylthiomethyl)-3cephem 4-carboxylic acid.

R 0.17 (t 0.10) in the system methylisobutylketone/methanol/formic acid 60/6/2, detection with bromcresol green and KMnO nmr 1.00 t (3H) (J 7.3 c./sec.), 2.70 s (3H), 3.00 q (2H) (J 7.3 c./sec.), 3.51 d (1H) (J 17 c./sec.), 3.88 d (1H) (J 17 c./sec.), 4.20 d (1H) (J 12 c./sec.), 4.58 d (1H) (J 12 c./sec.), 5.08 d (1H) (J 5.2 c./sec.), 5.68 d (1H) (J 5.2 c./sec.).

EXAMPLE 7 In a one litre reaction flask and to a 6.528 g aliquot of 7-amino-3-(2-thiazolin-2-ylthiomethyl)-3-cephem- 4-carboxylic acid prepared according to the procedure described in Example 3 are added methylene chloride (500 ml), triethylamine (5.6 ml) and ethylisocyanate (2.4 ml). The mixture is stirred at room temperature for 17 hrs and then at 50C for 1 hour. The solvent is then removed by evaporation under reduced pressure and the residue is taken up in acetic acid (20 ml) and ethylacetate (250 ml).

After filtration, ethyl ether is added to precipitate 7- (3-ethylureido)-3-(2-thiazolin-2-ylthiomethyl)-3- cephem-4-carboxylic acid.

R 0.17 (i 0.10) in the system methylisobutylketone/methanol/formic acid 60/6/2, detection with bromcresol green and KMnO nmr 1.18 t (3H) (J 7.0 c./sec.), 2.70-3.30 m (2H 2H), 3.01 q (2H) (J 7.0 c./sec.), 3.30 d (ll-I) (J 16 c./sec.), 3.70 d (1H) (J 16 c./sec.), 4.10 d (1H) (J 8 c./sec.), 4.35 d (1H) (J 8 c./sec.), 4.98 d (1H) (J 5 c./sec.), 5.58 d (1H) (J 5 c./sec.).

EXAMPLE 8 In a one litre reaction flask and to a 6.888 g aliquot of 7-amino-3-( 2-methyl-l ,3,4-thiadiazol-5- ylthiomethyl)-3-cephem-4-carboxylic acid prepared according to the procedure of Example 1, is added methylene chloride (500 ml), triethylamine (5.6 ml) and 2-chloro-ethylisocyanate (4.2 ml). The mixture is stirred for 10 hrs at room temperature. The solvent is then removed by evaporation under reduced pressure at a temperature inferior to 40C and the residue is taken up in acetic acid (20 ml) and ethyl acetate (250 m1).

After filtration, ethyl ether (2 l.) is added to precipitate 7-[3-(2-chloro-ethylureido)]-3-(2-methyl-1,3,4- thiadiazol-S-ylthiomethyl )-3-cephem-4-carboxylic acid (7.54 g), crys'tallizing with 1.5 mole of ether.

R, 0.49 (i 0.10) in the system acetonitrile/mcthanol/water 6/3/1, UV. detection; nmr 2.67 s (3H), 2.83.4 m (2H 2H), 3.39 d (1H) (J 16 c./sec.), 3.72 d (1H) (J 16 c./sec.), 4.21 d (1H) (J 13 c./sec.), 4.59 d (1H) (J 13 c./sec.), 5.01 d (1H) (J 5.3 c./sec.), 5.58 d (1H) (J 5.3 c./sec.).

Using the same procedure, the following cephalosporins are obtained:

7-[ 3 -(2-chloro-ethylureido)]-3-(2-methyl-1,3 ,4- oxadiazol-S-ylthiomethyl)-3-cehem-4-carboxylic acid nmr 2.47 s (3H), 3.40-3.75 m (2H 2H 2H), 4.38 s (2H), 5.06 d(1I-I) (J c./sec.), 5.75 d (1H) (J 5 c./sec.).

7-[3-(2-chloro-ethylureido)]-3-(2-methyl-1,3,4-

triazol-S-ylthiomethyl )-3-cephem-4-carboxylic acid nmr 2.66 s (3H), 3.40-3.80 m (2H 2H 2H), 4.20-4.60 m (2H), 5.01 d (1H) (J 5 c./sec.), 5.7 d (1H) (J 5.3 c./sec.).

7-[3-(2-chloro-ethylureido)]-3-(pyrimidin-Z- ylthiomethyl)-3-cephem-4-carboxylic acid nmr 3.51 d (1H) (J 18 c./sec.), 3.59 t (2H) (J 6.7 c./sec.), 3.65 t (2H) (J 6.7 c./sec.), 3.88 d (1H) (J 18 c./sec.), 4.08 d (1H) (J 13 c./sec.), 4.74 d (1H) (J 13 c./sec.), 5.11 d (11-1) (J 5.1 c./sec.), 5.78 d (1H) (J 5.1c./sec.), 7.29 t (1H) (J 5 c./sec.), 8.69 d (2H) (J 5.0 c./sec.).

7-[ 3-( 2-chloro-ethylureido)]-3-( 1,3,4-oxadiazol-2- ylthiomethyl)-3-cephem-4-carboxylic acid nmr 3.4-3.8 m (2H 2H 2H), 4.4 m (2H), 5.0 d (1H) (J 5 c./sec.), 5.58 d (1H) (J 5 c./sec.), 9.52 s (1H).

7-[ 3-( 2-chloro-ethylureido)]-3-( 1,3,4-triazol-2- ylthiomethyl)-3-cephem-4-carboxylic acid nmr 3.3-4.0 m (2H 2H 2H), 4.2-4.8 m (2H), 5.00 d (1H) (J 5 c./sec.), 5.55 d (1H) (J 5 c./sec.), 9.18 s (1H).

7-[ 3-( 2-chloro-ethylureido)]-3-( l-methyl- 1 H- tetrazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid nmr 3.33.4 m (2H 2H), 3.60 m (2H), 3.93 s

(3H), 4.3 m (2H), 4.95 d (II-I) (J 5 c./sec.), 5.53

d (1H) (J 5 c./sec.).

EXAMPLE 9 In a 1 litre reaction flask and to a 6.888 g. aliquot of 7-amino-3-(2-methyl-1,3 ,4-thiadiazol-5-ylthiomethyl 3-cephem-4-carboxylic acid prepared according to the procedure described in Example 1, is added n.propylisocyanate (2.9 ml) in pyridine (250 ml). The mixture is stirred for 4 hrs. at room temperature. The solvent is then removed by evaporation under reduced pressure and the residue is taken up in acetic acid (10 ml) and ethyl acetate (125 ml).

After filtration, ethyl ether isadded to precipitate 7- (3-n.propy1ureido)-3-(2-methyl-1,3 ,4-thiadiazol-5- ylthiomethyl)-3-cephem-4-carboxylicacid.

. R, 0.39 (i 0.10) ,in the system acetonitrile/water /20, detection with bromcresol green and KMnO nmr 0.83 t (3H) (J 6.6 c.'/sec.), 1.35 m (2H) (J 6.6

c./sec.), 2.70 s (3H), 3.03 t (2H) (J 6.6 c./sec.), 3.55 d (1H) (J 17 c./sec.), 3.85 d (1H) (J 17 c./sec.), 4.20 d (1H) (J 13 c./sec.), 4.56 d (1H) (J 13 c./sec.), 5.11 d (1H) (J 5.3 c./sec.), 5.70 d (1H) (J 5.3 c./sec.).

Using the same procedure, the following cehalosporins are obtained:

7-(3-n.propylureido)-3-(2-methyl-1,3 ,4-oxadiazol-5- ylthiomethyl)-3-cephem-4-carboxylic acid nmr 0.89 t (3H) (J 7.0 c./sec.), 1.4 m (2H) (J 7.0 c./sec.), 2.49 s (3H), 3.4 m (2H), 3.51 d (1H) (J 18 c./sec.), 3.86d (1H) (J 18 c./sec.), 4.38 s (2H), 5.12 d (1H) (J 5 c./sec.), 5.74 d (1H) (J 5 l c./sec.). 7-( 3-n.propylureido )-3-(pyrimidin-Z-ylthiomethyl 3-cephem-4-carboxylic acid nmr 0.86 t (31-1) (J 7.5 c./sec.),1.37 m (2H) (J 7.5

c./sec.), 3.06 t (2H) (J 7.5 c./sec.), 3.50 d (1H) (J 16.5 c./sec.), 3.89 d (1H) (J 16.5 c./sec.), 6.02 d (1H) (J14 c./sec.), 6.70 d (1H) (J 14 c./sec.), 5.08 d (1H) (J 4.9 c./sec.), 5.73 d (1H) (J 4.9 c./sec.), 7.25 t (1H) (J 5 c./sec.), 8.57 d (2H) (J 5 c./sec.).

7-( 3-n.propylureido)-3-( 1,3,4-oxadiazol-2- ylthiomethyl)-3-cephem-4-carboxylic acid nmr 0.89 t (3H) (J 7.3 c./sec.), 1.4 m (2H) (J 7.3 c./sec.), 3.1 t (2H) (J 7.3 c./sec.), 3.48 d (1H) (J 17 c./sec.), 3.84 d (1H) (J 17 c./sec.), 4.29 d (1H) (J 13 c./sec.), 4.56 d (1H) (J 13 c./sec.), 5.09 d (1H) (J 5.3 c./sec.), 5.74 d (1H) (J 5.3 c./sec.).

7-(3-n.propylureido)-3-(1-methyl-1,3,4-triazol-2- ylthiomethyl)-3-cephem-4-carboxylic acid nmr 0.86 t (3H) (J 7 c./sec.), 1.3 m (2H), 3.25 m (2H), 3.60 m (2H), 3.97 s (3H), 4.32 m (2H), 5.00 d (1H) (J 5.2 c./sec.), 5.59 d (1H) (J 5.2 c./sec.).

EXAMPLE 10 In a 1 litre reaction flask and to 5.360 g. of 7-amino- 3-desacetoxy-cephalosporanic acid (7-ADCA) are added chloroform (250 ml), triethylamine (10 ml) and isopropylisocyanate (3.7 ml). The mixture is heated to 50C for 10 hrs. The unreacted 7-ADCA is separated by filtration. The solvent is removed by evaporation under reduced pressure, the residue is dissolved in acetone and precipitated by addition of ethyl ether.

After filtration, the precipitate is taken up in acetic acid (30 ml) from which 7-(3-isopropylureido)-3- desacetoxy-cephalosporanic acid precipitates by addition of ethyl ether (200 ml).

R 0.25 (i 0.10) in the system methylisobutylketone/methanol/formic acid 60/6/2, detection with bromcresol green and KMnO nmr.: 1.04 d (6H) (J 6.6 c./sec.), 2.01 s (3H), 2.8-3.5 m (1H) (J 6.6 c./sec.), 3.29 d (1H) (J 15.5 c./sec.), 3.67 d (1H) (J 15.5 c./sec.), 5.02 d (1H) (J 4.8 c./sec.), 5.60 d (1H) (J 4.8 c./sec.).

EXAMPLE 1 1 In a one litre reaction flask and to a 6.888 g. aliquot of 7-amino-3-(2-methyl-1,3 ,4thiadiazol-5- ylthiomethyl)-3-cephem-4-carboxylic acid prepared according to the procedure described in Example 1, is added isopropylisocyanate (3 ml) in pyridine (500 ml). the mixture is heated to 50C and stirred for 6 hrs at that temperature. The solvent is then removed by evaporation under reduced pressure and the residue is taken upin acetic acid (20ml) and ethyl acetate (250ml).

After filtration, ethyl ether is added to precipitate 7- (3-isopropylureido)-3-(2-methyl-1,3,4-thiadiazol-5- ylthiomethyl)-3-cephem-4-carboxylic acid (5.78 g).

R,= 0.19 (i 0.10) in the system methylisobutylketone/methanol/formic. acid 60/6/2, detection with bromcresol green and KMnO nmr 1.05 d (6H) (J 6.6 c./sec.), 2.69 s (3H), 2.8-3.5 m (1H) (J 6.6 c./sec.), 3.49 d (1H) (J c./sec.), 3.85 d (1H) (J 15 c./sec.), 4.23 d (1H) (J 13 c./sec.), 4.59 cl (1H) (J 13 c./sec.), 5.10 d (1H) (J 5.2 c./sec.), 5.71 d (1H) (J 5.2 c./sec.).

EXAMPLE 12 In a one litre reaction flask and to a 6.528 g. aliquot of 7-amino-3-(2-thiazolin-2-ylthiomethyl)-3-cephem- 4-carbox'ylic acid prepared according to the procedure described in Example 3, are added methylene chloride (500 ml), triethylamine (5.6 ml) and isopropylisocyanate (3 ml). The mixture is stirred at room temperature for 18 hrs. The solvent is then removed by evaporation under reduced pressure and the residue is taken up in acetic acid ml) and ethyl acetate (250 ml).

After filtration, ethyl ether is added to the filtrate to precipitate 7-( 3-isopropylureido )-3-( 2-thiazolin-2- ylthiomethyl)-3-cephem-4-carboxylic acid.

R 0.24 (:t 0.10) in the system methylisobutylketone/methanol/formic acid 60/6/2, detection with bromcresol green and KMnO nmr 1.05 d (6H) (J 6.6 c./sec.), 2.8-3.5 m (2H 2H +1H), 3.30 d (1H) (J 14 c./sec.), 3.65 d (1H) (J 14 c./sec.), 4.07 d (1H) (J 15 c./sec.), 4.40 d (1H) (J 15 c./sec.), 4.98 d (1H) (J 5.2 c./sec.), 5.57 d (1H) (J 5.2 c./sec.).

EXAMPLE 13 In a one litre reaction flask and to 5.360 g. of 7- amino-3-desacetoxy-cephalosporanic acid (7-ADCA) are added pyridine (500 ml) and allylisocyanate (3.3 ml). The mixture is heated to 50C for 5 hrs. The solvent is removed by evaporation under reduced pressure, the residue 'is taken up in acetic acid (20 ml) and ethyl acetate (250 ml) from which 7-(3-allylureido)-3- desacetoxy-cephalosporanic acid (6.480 g) precipitates by addition of ethyl ether (100 m1).

R,= 0.28 (i 0.10) in the system methylisobutylketone/methanol/formic acid 60/6/2; detection with bromcresol green and KMnO nmr 2.00 s (3H), 3.26 d (1H) (J 17 c./sec.), 3.65 d(1I-I) (J 17 c./sec.), 3.5-3.9 m (2H), 5.02 d (1H) (J 4.6 c./sec.), 5.0-5.4 m (2H), 5.6 d (1H) (J 4.6 c./sec.), 5.6-5.9 m (1H).

EXAMPLE 14 In a one litre reaction flask and to a 6.528 g. aliquot of 7-amino-3-(2-thiazolin-2-yl)-3-cephem-4-carboxylic acid prepared according to the procedure described in Example 3 are added chloroform (500 ml), triethylamine (5.6 ml) and allylisocyanate (2.65 ml). The mixture is stirred at room temperature for 3 hrs. The solvent is removed by evaporation under reduced pressure and the residue is taken up in acetic acid (20 ml) and ethyl acetate (250 ml). n

After filtration, ethyl ether is added to the filtrate to precipitate 7-(3-allylureido)-3-(2-thiazolin-2- ylthiomethyl)-3-cephem-4-carboxylic acid.

R;= 0.14 (i 0.10) in the system methylisobutylketone/methanol/formic acid 60/6/2, detection with bromcresol green and KMnO nmr 3.3-3.9 m (2H 2H 2H), 3.9-4.2 m (2H), 4.08 d (1H) (J 12 c./sec.), 4.40

d (1H) (J 12 c./sec.), 4.98 d (1H) (J 5 c./sec.), 5.0-5.4 m (2H), 5.62 d (1H) (J 5 c./sec.), 5.7-6.0 m (1H).

EXAMPLE 15 In a 1 litre reaction flask and to a 6.888 g. aliquot of 7-amino-3-( 2-methyll ,3 ,4-thiadiazol-5-ylthiomethyl)- 3-cephem-4-carboxylic acid prepared according to the procedure described in Example 1, is added allylisocyanate (2.65 ml) in methylene chloride 500 ml) and triethylamine (5.6 ml). The mixture is stirred for 18 hrs at room temperature. The solvent is then removed by evaporation under reduced pressure and the residue is taken up in acetic acid 20 ml) and ethyl acetate (250 ml).

After filtration, ethyl ether is added to precipitate 7- (3-allylureido)-3-(2-methyl-l ,3 ,4-thiadiazol-5- ylthiomethyl)-3-cephem-4-carboxylic acid.

R,= 0.12 (i 0.10) in the system methylisobutylketone/methanol/formic acid 60/6/2, detection with bromcresol green and KMnO nmr 2.68 s (3H), 3.40-3.90 m (21-1 2H), 4.22 d (1H) (J 13 c./sec.), 4.60 d (ll-I) (J 13 c./sec.), 5.0-5.40 m (2H), 5.01 d (1H) (J 5 c./sec.), 5.68 d (1H) (J 5 c./sec.), 5.7-6.0 m (1H).

Using the same procedure, the following cephalosporins are obtained:

7-( 3-allylureido )-3-( 2-methyll ,3 ,4-oxadiazol-5- ylthiomethyl)-3-cephem-4-carboxylic acid nmr 2.47 s (3H), 3.4-3.8 m (2H+ 2H), 6.22 d (1H) (J 18.6 c./sec.), 6.52 d (1H) (J 18.6 c./sec.), 5.00 d (1H) (J 5.3 c./sec.), 5.0-5.2 m (2H), 5.7 d (1H) (J 5.3 c./sec.), 5.6-6.2 m (2H). 7-(3-allylureido)-3-(2-methyl-1,3 ,4-triazol-5 ylthiomethyl)-3-cephem-4-carboxylic acid nmr 2.62 s (3H), 3.3-4.05 m (2H 2H +2H), 5.01 d (ll-I) (J 5.3 c./sec.), 5.20 m (2H), 5.68 d (1H) (J 5.3 c./sec.), 5.8-6.3 m (1H) 7-(3-allylureido)-3-(pyrimidin-Z-ylthiomethyl)-3- cephem-4-carboxylic acid nmr 3.50 d (1H) (J 18 c./sec.), 3.92 d (1H) (J 18 c./sec.), 4.07 d (1H) (J 14 c./sec.), 4.73 d (1H) (J 14 c./sec.), 4.9-5.3 m (2H), 5.12 d (1H) (J 5 c./sec.), 5.6-6.3 m (1H), 5.80 d (1H) (J 5 c./sec.), 7.3 t (1H) (J 5.2 c./sec.), 8.7 d (2H) (J 5.2 c./sec.).

7-( 3-allylureido)-3-( l-methyl- 1 H-tetrazol-S- ylthiomethyl)-3-cephem-4-carboxylic acid nmr: 3.66 m (2H), 3.96 s (3H), 4.35 m (2H), 5.0 d

(1H) (J 5 c./sec.), 5.27 m (2H), 5.60 d (1H) (J 5 c./sec.), 5.60-6.2 m (1H).- 7-(3-allylureido)-3-(1,3,4-oxadiazol-2- ylthiomethyl )-3-cephem-4-carboxylic acid nmr: 3.70 m (2H), 4.4 m (2H), 4.99 d (1H) (J 5 c./sec.), 5.22 m (2H), 5.57 d (1H) (J 5 c./sec.), 5.60-6.10 m (1H), 9.5 s (1H). 7-(3-allylureido)-3-( I ,3,4-triazol-2-ylthiomethyl)-3- cephem-4-carboxylic acid nmr 3.75 m (2H), 4.3 m (2H), 5.10 d (1H) (J 5 c./sec.), 5.32 m (2H), 5.72 d (1H) (J 5 c./sec.), 5.70-6.15 m (1H), 9.25 s (1H).

EXAMPLE 16 In a 1 litre reaction flask and to a 6.888 g. aliquot of 7-amino-3-( Z-methyl-l ,3,4-thiadiazol-5-ylthiomethyl)- 3-cephem-4-carboxylic acid prepared according to the procedure described in Example 1, is added n.butylisocyanate (3.3 ml) in pyridine (500 ml). The mixture is heated to C and stirred for one hour at that temperature. The solvent is then removed by evaporation under reduced pressure and the residue is taken up in acetic acid ml) and ethyl acetate (250 ml).

After filtration, ethyl ether is added to the filtrate to precipitate 7-( 3-n.butylureido)-3-(2-methyl-l ,3,4- thiadiazol-S-ylthiomethyl)-3-cephem-4-carboxylic acid.

R, 0.48 (i 0.10) in the system acetonitrile/water 80/20, detection with bromcresol green and KMnO nmr 0.88 t (3H) (J 6 c./sec.), 1.0-1.5 m (2H 2H) (J 6 c./sec.), 2.67 s (3H), 3.02 m (2H) (J 6 c./sec.), 3.52 d (1H) (J 14 c./sec.), 3.83 d (1H) (J 14 c./sec.), 4.21 d (1H) (J 13 c./sec.), 4.61 d (1H) (J 13 c./sec.), 5.10 d (1H) (J 5.2 c./sec.), 5.65 d (1H) (J 5.2 c./sec.).

EXAMPLE l7 7-ACA (13.65 g) and 5-mercapto-2-methyl-l ,3,4- triazole (8.15 g) are suspended in 500 ml. of phosphate buffer 0.2 M (Na HPO NaH PO pH 6.5. To the suspension are added with stirring 10.93 g. of NaHCO The reaction medium is heated for 80 minutes with stirring on a 80C water bath. The solution is then treated with charcoal, cooled (5l0C) and acidified to pH 4 with 2 N hydrochloric acid. The obtained suspension is diluted with 150 ml. of acetone and stirred for 30 minutes. The precipitate is filtered, washed with water, acetone and ethyl ether and dried under reduced pressure to yield 7-amino-3-(2-methyl-1,3 ,4-triazol- 5- ylthiomethyl)-3-cephem-4-carboxylic acid.

EXAMPLE 18 In a 1 litre reaction flask and to a b 6.528 g. aliquot of 7-amino-3-(2-methyl-l,3,4-triazol-5-ylthiomethyl)- 3-cephem-4-carboxylic acid prepared according to the procedure described in Example 17, are added pyridine (500 ml) and n.butylisocyanate (4.4 ml). The mixture is stirred at room temperature for 3 hrs. The solvent is then removed by evaporation under reduce pressure at a temperature inferior to 40C and the residue is taken up in acetic acid (20 ml) and methanol (250 ml).

After filtration on charcoal, ethyl ether is added to the filtrate to precipitate 7-(3-n.butylureido)-3-(2- methyl-l ,3 ,4-triazol-5-ylthiomethyl )-3-cephem-4- carboxylic acid.

R, 0.51 (i 0.10) in the system acetonitrile/methanol/water 6/3/1, U.V. detection; nmr 0.89 t (3H) (J 6.5 c./sec.), 1.1-1.7 m (2H +2H), 2.35 s (3H), 3.13 t (2H) (J 6 c./sec.), 3.28 d (1H) (J 18 c./sec.), 3.75 d (1H) (J 18 c./sec.), 3.85 d (1H) (J 14 c./sec.), 4.17 d (1H) (J 14 c./sec.), 5.03 d (1H) (J 5.2 c./sec.), 5.54 d (1H) (J 5.2 c./sec.).

EXAMPLE19 In a 1 litre reaction flask and to a 6.888 g. aliquot of 7-amino-3-( 2-methyl- 1 ,3 ,4-thiadiazol-5-ylthiomethyl 3-cephem-4-carboxylic acid prepared according to the procedure described in Example 1, are added pyridine (500 ml) and n.hexylisocyanate (5.1 ml). Themixture is stirred to 70C for 1 hour. The solvent is then removed by evaporation un-der reduced pressure at a temperature inferior to 40C and the residue is taken up in acetic acid (20 ml) and ethyl acetate (250 ml).

After filtration, ethyl ether (270 ml) is added to the filtrate and the solvent is removed by evaporation under reduced pressure. The residue is taken up in ethanol (250 ml) and the solution is filtered on charcoal and concentrated by evaporation. By addition of water,

7-(3-n.hexylureido)-3-(2-methyl-1,3,4-thiadiazol-5- ylthiomethyl)-3-cephem-4-carboxyli.c acid (5.85 g) is obtained.

R, 0.58 (i 0.10) in the system acetonitrile/methanol/water 6/3/1, U.V. detection; nmr 0.88 t (3H) (J 5.9 c./sec.),,l.28- m (4 X 2H), 2.68 's (3H), 2.98 t (2H) (J 6.0 c./sec.), 3.51 d (1H) (J 17 c./sec.), 3.87 d (1H) (J 17 c./sec.), 4.21 d (1H) (J 13 c./sec.), 4.61 d (1H) (J 13 c.-/sec.), 5.09 d (1H) (J 5.2 c./sec.), 5.70 d (1H) (J 5.2 c./sec.).

EXAMPLE 20 In a 1 litre reaction flask and to 6.888 g. aliquot of 7-amino-3-( 2-methyl-1 ,3,4- thiadiazol-5-ylthiomethyl 3-cephem-4-carboxylic acid prepared according to the procedure described in Example 1, are added pyridine (500 ml) and benzylisocyanate (4 rnl). The mixture is stirred at room temperature for 1 hour. The solvent is then removed by evaporation under reduced pressure at temperature inferior to 40 C and the residue is taken up in acetic acid (20 ml) and ethyl acetate (250 ml). 1

After filtration, the solvent is evaporated under reduced pressure. The residue is taken up in methanol ml) and by addition of ethyl ether (2 l.) 7-(3- benzylureido)-3-(2-methyl-1,3 ,4-thiadiazol-5- ylthiomethyl)-3-cephem-4-carboxylic acid is obtained.

R, 0.56 0.10) in the system acetonitrile/methanol/water 6/3/1, detection with bromcresol green and KMnO nmr 2.65 (3H), 3.4 m (2H), 4.3 m (2 X 2H), 5.0 d (1H) (J 4.9 c./sec.), 5.68 d (1H) (J 4.9 c./sec.), 7.25 m (5H).

Using the same procedure, the following cephalosporins are obtained:

7-(3-benzylureido)-3-(2-methyl-1,3,4-oxadiazol-5- ylthiomethyl)-3-cephem-4-carboxylic acid nmr 2.45 s (3H), 3.60 d (1H) (J 16 c./sec.), 3.86 d (11-1) (J 16 c./sec.), 4.27 m (2H +2H), 5.10 d (1H) (J 5 c./sec.), 5.73 d (1H) (J 5 c./sec.), 7.31 s (5H). 7-( 3-benzylureido)-3-( pyrimidin-Z-ylthiomethyl )-3- cephem-4-carboxylic acid nmr: 3.48 d (1H) (J 17.4 c./sec.), 3.88 d (1H) (J 17.4 c./sec.), 4.06 d (1H) (J 13 c./sec.), 4.32 s (2H), 4.72 d (1H) (J 13 c./sec.), 5.10 d (1H) (J 5.1 c./sec.), 5.76 d (1H) (J 5.1 c./sec.), 7.22 t (1H) (J 5 c./sec.), 7.32 s (5H), 8.67 d (2H) (J 5 c./sec.). 7-(3-p-acetoxybenzylureido)-3-('2-methyl-1,3,4-

thiadiazol-S-ylthiomethyl)-3-cephem-4-carboxylic acid nmr 2.24 s (3H), 2.66 s (3H), 3.52 m (2H), 4.27 s (2H), 4.22 d (1H) (J 13 c./sec.), 4.58 d (1H) (J 13' c./sec.), 500 d (1H) (J 5 c./sec.), 5.59 cl (1H) (J 5 c./sec.), 7.14 d (2H) (J 8.5 c./sec.),' 7.40 d (2H) (J 8.5 c./sec.). 7-(3 -p-hydroxybenzlureido)-3-(2-methyl-1 ,3 ,4-

thiadiazol-S-ylthiomethyl)-3-cephem-4-carboxylic .acid nmr 2.70 s (31-1), 3.72 m (1H +11-1), 4.18 s (2H), 4.25 d (1H) (J 14 c./sec.), 4.62 d (1H) (J 14 c./sec.), 5.15 d (1H) (J 5 c./sec.), 5.76 d (1H) (J 5 c./sec.), 6.82 d (2H) (J 9 c./sec.), 7.20 d (2H) (J 9 c./sec.). 7-(3-a-methylbenzylureido)-3-(2-methyl-1,3,4-

thiadiazol-S-ylthiomethyl)-3-cephem-4-carboxylic acid.

nmr: 1.35 d (3H) (J 7 c./sec.), 2.68 s (3H), 3.55 d. (1H) (J 17 c./sec.), 3.88 d (1H) (J17 c./sec.), 4.27

d:( 11-1) (J 13 c./s ec.), 4.6 d (11-1) (J 13 c./sec.), 4.8 I

7-amino-3-( 2-methyl-1 ,3 ,4-thiadiazol-5 -ylthiomethyl 3-cephem-4-carboxylic acid prepared according to the procedure described in Example 1, is added pfluorophenylisocyanate (2.9 ml) in methylene chloride (500 ml) and triethylamine (5.6 ml); The mixture is stirred at room temperature for 1% hr. The solvent is then removed by evaporation under reduced pressure and the residue is taken up in acetic acid (20 ml) and ethyl acetate (250 ml).

After filtration, ethyl ether is added to precipitate 7- (3-p-fluorophenylureido)-3-(2-methyl-1,3,4- thiadiazol-S-ylthiomethyl)-3-cephem-4-carboxylic acid.

R 0.29 (i 0.10) in the system methylisobutylketone/methanol/formic acid 60/6/2, detection with bromcresol green and KMnO nmr 2.68 s (31-1), 3.41 d (1H) (J 12 c./sec.), 3.70 d (1H) (J 12 c./sec.), 4.29 d (1H) (J 13 c./sec.), 4.62 d (1H) (J 13 c./sec.), 5.08 d (1H) (J 5.3 c./sec.), 5.72 d (1H) (J 5.3 c./sec.), 6.8-7.6 m (4H).

EXAMPLE 23 In a 1 litre reaction flask and to 5.360 g of 7-amino-3- desacetoxy-cephalosporanic acid (7-ADCA) are added pyridine (500 ml) and cyclohexylisocyanate (4.8 ml). The mixture is heated at 50 C for 4 hrs and at 70 C for 3 hrs. The solvent is removed by evaporation under reduced pressure, the residue is taken up in acetic acid (20 ml) and ethyl acetate (250 ml) from which 7-(3- cyclohexylureido)-3-desacetoxycephalosporanic acid precipitates by addition of ethyl ether (1 litre).

R 0.37 (i 0.10) in the system methylisobutylketone/methanol/formic acid 60/6/2, detection with bromcresol green and KMnO nmr 1.0-1.8 m (6H), 1.4-2.1 m (4H), 2.04 s (3H), 3.31 d (111) 014.7 c./sec.), 3.4-3.9 m (1H), 3.66 d (1H) (J 14.7 c./sec.), 5.04 d(1l-l) (J 5.3 c./sec.), 5.61 cl (1H) (J 5.3 c./sec.).

EXAMPLE 24 In a 1 litre reaction flask and to a6.888 g aliquot of 7-amino-3-(2-methyl-1,3 ,4-thiadiazol-5-ylthiomethyl 3-cephem-4 -carboxylic acid prepared according to the procedure described in Example 1, is added cyclohexylisocyanate (3.8 ml) in pyridine (500 ml). The mixture is heated to 70 C and stirred for one hour at that temperature. The solvent is then removed by evaporation under reduced pressure and the residue is taken up in acetic acid (20 ml) and ethyl acetate (250 ml).

After filtration, ethyl ether is added to precipitate 7- (3-cyclohexylureido)-3-(2-methyl-1,3 ,4-thiadiazol-5- ylthiomethyl)-3-cephem-4-carboxylic acid.

R,= 0.46 (i 0.10) in the system acetonitrile/water 80/20, detection with bromcresol green and KMnO nmr 0.8-1.6 m (61-1), 1.2-2.0 m (4H), 2.73 s (3H), 3.0-3.7 m (1H), 3.5-4.0 m (2H), 4.23 d (1H) (J 14.7 c./sec.), 4.60 d (1H) (J 14.7 c./sec.), 5.1 l d 11-1) (J 5.0 c./sec.), 5.71d(1H) (J 5.0 c./sec.).

EXAMPLE 25 When an equivalent amount of 2- cyanoethylisocyanate, ethoxycarbonylmethylisocyanate, 3-butoxypropylisocyanate, 3-

p-cyanophenylisocyanate,

p-mercaptophenylisocyanate, p-methoxyphenylisocyanate, B-cyclohexylethylisocyanate, 2- chlorocyclohexylisocyanate, 3- cyclohexenylisocyanate, l,2-dibromoethylisocyanate, p-methylthiophenylisocyanate, pdimenthylaminophenylisocyanate, 9'ethyl-3- carbazolylisocyanate (prepared according to Werner Siefken Ann. 562, -136, 1949) is substituted for methylisocyana te in the procedure of Example 2, the following cephalosporins are obtained 7-[3-(2-cyanoethyl)ureido]-3-[2-methyl-1.3,4-

thiadiazol5-ylthiomethyl]-3-cephem-4-carboxylic acid .7-[3-ethoxycarbo nylmethyl. ureido]-3-[2-methyl- 1,3,4-thiadiazol5-ylthiomethyl]-3-cephem-4- carboxylic acid 7-[3-(3-butoxypropyl)ureido]-3-[2-methyl-1,3,4-

thiadiazol-S-ylthiomethyl]-3-cephem-4-carboxylic acid 7-[ 3-( 3-nitropropyl )ureidol-3-[2-inethyl-1 ,3,4-

thiadiazol-5-ylthiomethyl]-3-cephem-4-carboxylic acid 7-[3-(2-dimethylaminoethyl)ureido]-3-[2-methyl- 1,3,4-thiadiazol-5-ylthiomethyl ]-3-cephem-4- carboxylic acid t 7-[ 3-( p-nitrophenyl )ureido]-3-[2-methyl-l ,3,4-

thiadiazol-S-ylthiomethyl]-3-cephem-4-carboxylic acid 7-[3-(p-acetamidophenyl)ureido]-3[2-methyll,3,4-thiadiazol-5-ylthiomethyl]-3-cephem 4 carboxylic acid 7-[3-(p-hydroxypheny1)ureido] -3- [Z-methyll ,3 ,4-

thiadiazol-S-ylthiomethyl]-3-cephem4-carboxylic acid 7-[3-(p-cyanophenyl)ureido1-3-[2-methyl-1,3,4

thiadiazol-S-ylthiomethyl]-3-cephem-4-carboxylic acid 7-[3-(p-sulfamoylphenyl)ureido]-3-[2-methyl-1,3 ,4-

thiadiazol-5-ylthiomethyl]-3-cephem-4-carboxylic acid 7-[3-(p-mercaptophenyl)ureido]-3-[2-methyl-1,3 ,4-

thiadiazol-S-ylthiomethyl]-3-cephem-4-carboxylic acid 7-[3-(p-methoxyphenyl)ureido]-3-[2-methyl-1,3,4-

thiadiazol-5-ylthiomethyl]-3-cephem-4-carboxylic acid 7-[3-(B-cyclohexylethyl)ureido]-3-[2-methyl-1,3,4-

thiadiazol-S-ylthiomethyl ]-3-cephem-4-carboxylic acid 7- [3-(2-chlorocyclohexyl)ureido]-3{2-methyl- 1 ,3,4-thiadiazol-5 -ylthiomethy1l-3-cephem-4- carboxylic acid 1 7-[3 (3 -cyclohexenyl)ureido] -3-[2-methyl-1 ,3 ,4-

thiadiazol-S-ylthiomethyl]-3-cephem-4-carboxylic acid 7-[ 3-( 1,2-dibromoethyl)ureido]-3-[2-methyl-1 ,3,4-

thiadiazol-S-ylthiomethyl]-3-cephem-4-carboxylic acid 7-[3-(p-methylthiophenyl)ureido]-3-[2-methyl- 1,3 ,4-thiadiazol-5-ylthiomethyl]-3-cephem-4- carboxylic acid 7-[3-(p-dimethy1aminophenyhureido]-3-[2-methy1' 1 ,3,4-thiadiazol-5-y1thiomethyl]-3-cephem-4- carboxylic acid 7-[3-(9-ethyl-3-carbazoly)ureido]-3-[2-methyl- 1,3,4-thiadiazolyl-5-ylthiomethyl]-3-cephem-4- carboxylic acid EXAMPLE 26 When an equivalent amount of l,2,2,2,-tetrachloroethylisocyanate (prepared according to Henri Ulrich et al., Angew. Chem. Int. Ed. Engl. 6(7), 6367, 1967) is substituted for methylisocyanate in the procedure of Example 2, the following cephalosporin is obtained 7- [3-(1,2,2 ,2-tetrachloroethyl)ureido] -3 -[2-methyl- 1,3 ,4-thiadiazol-S-ylthiomethyl]-3 cephem-4- carboxylic acid.

. EXAMPLE 27 EXAMPLE 28 When an equivalent amount of a-chlorostyrylisocyanate (prepared according to Ohoka M. et al., J. Org. Chem. 36(23), 3542-46, 1971) is substituted for methylisocyanate-in' the procedure of Example 2, the following cephalosporin is obtained: 7-[3-(a-chlorostyryl furyl )ureido]-3-[2-methyl-l ,3,4-thiadiazol-- ylthiomethyl]-3-cephem-4-carboxylic acid.

EXAMPLE 29 When an equivalent amount of 5-nitro-2- furylisocyanate (prepared according to Saikachi Harno et al., Yakugaku Zasshi 88(9), ll8996, 1968) is substituted for methylisocyanate in the procedure of example 2,- the following cephalosporin is obtained: 7-[3-(5- nitro-2-furyl)ureido]-3-[2-methyl-1,3 ,4-thiadiazol-5- ylthiomethyl]-3-cephem-4-carboxylic acid.

EXAMPLE 3O 'When an equivalent amount of a-bromobenzylisocyanate, a-methoxybenzylisocyanate, a-hydroxybenzylisocyanate, a-azidobenzylisocyanate, a-carboxybenzylisocyanate, a-aminobenzylisocyanate (prepared according to Melvin S Newman, J. Amer. Chem. Soc. 57, 732-5, 1935) is substituted for methylisocyanate in the procedure of Example 2, the following cephalosporins were obtained:

7-[3-(a-bromobenzyl)ureido]-3-[2-methyl-1,3,4-

thiadiazol-S-ylthiomethyl]-3-cephem-4-carboxylic acid 7-[.3-(a-methoxybenzyl)ureido]-3-[2-methyl-1,3,4-

thiadiazol-5-ylthiomethyl -3-cephem-4-carboxylic acid 7-[ 3-(a-hydroxybenzyl )ureido]-3-[2-methyl-l ,3,4-

thiadiazol-S-ylthiomethyl]-3-cephem-4-carboxylic acid 7-[3v(a-azidobenzyl)ureido]-3-[2-methyl-1,3,4-

thiadiazol-S-ylthiomethyl]-3-cephem-4-carboxylic acid 7-[ 3-( a-carboxybenzyl )ureido]-3-[2-methyl-l ,3,4-

' thiadiazol-S-ylthiomethyl]-3-cephe-m-4-carboxylic acid 7-[ 3-(a-aminobenzyl )u'reido] l3-[2-methyl-l ,3,4-

thiadia'Zol-S-ylthiomethyl]-3-cephem-4-carboxylic acid EXAMPLE 31 When an equivalent amount of hydroxymethylisocyanate (prepared according to F. W. Hoover et al., J; Org. Chem. 28(7). 1825-30. 1963) is substituted for methylisocyanate in the procedure of Example 2, the following cephalosporin is obtained:

7-[3-hydroxymethylureido]-3-[Z-methyl-l ,3 ,4- thiadiazol-S-ylthiomethyl ]-3-cephem-4-carboxylic acid EXAMPLE 32 When an equivalent amount of one of the heterocyclic thiols listed below is substituted for 5-mercapto-2- methyl-1,3,4-thiadiazole in the procedure of Example l, the correspondingg 7-amino-3- (heterocyclicthiomethyl)-3-cephem-4-carboxylic acid is obtained: 2-mercapto-5-methyl-l ,3,4-oxadiazole 2-mercapto-l ,3 ,4-oxadiazole 3-mercapto-5-methyl-l ,2,4-thiadiazole 3-mercapto-l ,2,4-thiadiazole S-mercapto-l ,2,4-thiadiazole 2-mercapto-1,3 ,4-thiadiazole 2-mercaptopyrimidine 2-mercapto-4-methylpyrimidine 2-mercapto-5-methylpyrimidine 2-mercapto-S-methoxypyrimidine 4-mercapto-5,6-dim ethoxypyrimidine 3-mercaptopyridazine 3-mercapto-6-methylpyridazine 6-bromo-3-mercaptopyridazine 2-mercaptopyridine 4-mercaptopyridine 2-mercapto-6-methylpyridine 2-mercapto-5-nitropyridine 2-mercapto-4-methylthiazole EXAMPLE 33 When an equivalent amount of the appropriate 7- amino-3-(heterocyclicthiomethyl)-3-cephem-4- carboxylic acid of Example 32 is substituted for 7- amino-3-(2-methyl-l ,3,4-thiadiazol-5 -ylthiomethyl)-3- cephem-4-carboxylic acid in the procedure of Example 1, the following cephalosporins are obtained:

7-( 3-n.propylureido )-3-(5-methyl-l ,2,4-thiadiazol-3- ylthiomethyl )-3-cephem-4-carboxylic acid 7-(3-n.propylureido)-3-(1,2,4-thiadiazol-3- ylthiomethyl)-3-cephem-4-carboxylic acid 7-(3-n.propylureido)-3-(1,2,4-thiadiazol-5- ylthiomethyl)-3-cephem-4-carboxylic acid 7-(3-n.propylureido )-3-( l ,3,4-thiadazol-2- ylthiomethyl)-3-cephem-4-carboxylic acid 7-( 3-n.propylureido )-3-(4-methylpyrimidin-2- ylthiomethyl )-3-cephem-4-carboxylic acid 7-(3-n.propylureido )-3-(S-methylpyrimidin-Z- ylthiomethyl)-3-cephem-4-carboxylic acid 7-( 3 -n .propylureido )-3-( 5 -methoxypyrimidin-2- ylthiomethyl)-3-cephem-4-carboxylic acid 7-(3n.propylureido)3-(5,6-dimethoxyprimidin-4- ylthiomethyl)-3-cephem-4-carboxylic acid 7-( 3 -n.propylureido )-3-( pyridazin-3 -ylthiomethyl 3-cephem-4-carboxylic acid 7-(3-n.propylureido)-3-(6-methylpyridazin-3- ylthiomethyl)-3-cephem-4-carboxylic acid -7.-( 3-n.propylureido )-3-(6-bromopyridazin-3- ylthiomethyl)-3-eephern-4-carboxylid acid H 25 7-(3-n.propylureido)-3-(pyrid-2-ylthiomethyl)-3- cephem- 4-carboxylic acid 7-(3-n.propylureido)-3-(pyrid-4-ylthiomethyD-3- cephem-4-carboxylic acid 7-(3-n.propylureido)-3- (6-methylpyrid-2-ylthiomethyl)-3-cephem-4- carboxylic acid 7-(3-n.propylureido)-3-(5-nitr0pyrid-2- ylthiomethyl)-3-cephem-4-carboxylic acid 7-(3n.propylureido)-3-(4-methypyrid-2- ylthiomethyl)-3-cephem-4-carboxylic acid EXAMPLE 34 When an equivalent amount of one of the heterocyclic thiols listed below is substituted for -mercapto-2- methyl-1,3,4-thiadiazole in the procedure of Example 1, the corresponding 7-amino-3- (heterocyclucthiomethyl )-3-cephem-4-carboxylic acid is obtained: 2-mercapto-s-triazine 2-mercapto-4-methyl-s-triazine 3-mercapto-as-triazine 5,6-dimethyl-3-mercapto-as-triazine l ,5-dimethyl-3-mercaptopyrazole 2-mercapto-3-methoxypyrazine S-mercapto-l -methyl- 1 ,2,3-triazole Z-mercapto-S-methyl-1,3,4-triazole B-mercapto-l -methyl-1 ,2,4-triazole 1-propyl-1H-tetrazole-S-thiol 3-mercaptol -methyl-l ,2,4-triazole 3-mercapto-5-methyl-l ,2,4-triazole 3-mercapto-1 ,S-dimethyl-l ,2,4-triazole 2-mercapto-l ,3 ,4-triazole S-mercapto-l ,2,3-triazole 3-mercapto-l ,2,4-triazole S-mercaptotetrazole Z-mercaptopyrazine EXAMPLE 35 When an equivalent amount of the appropriate 7- amino-3-(heterocyclicthiomethyl)-3-cephem-4- carboxylic acid of Example 34 is substituted for 7- amino-3-( 2-methyll ,3,4-thiadiazol-5-ylthiomethyl)-3- cephem-4-carboxylic acid in the procedure of Example 20, the following cephalosporins are obtained:

7-(3-benzylureido)-3-(s-triazin-2-ylthiomethyl)-3- cephem-4-carboxylic acid 7-(3-benzylureid0)-- -benzylureido)-3(s-triazin-2-ylthiomethyl)-3- cephem-4-carboxylic acid 7-(3-benzylureido)-3-(as-triazin-3-ylthiomethyl)-3- cephem-4-carboxylic acid 7-(3-benzylureido)-3-(5,6-dimethyl-as-triazin-3- ylthiomethyl )-3-cephem-4-carboxylic acid 7-(3-benzylureido)-3-(1,5-dimethylpyrazol-3- ylthiomethyl)3-cephem-4-carboxylic acid 7-(3-benzylureido)-3-(3-methoxypyrazin-2- ylthiomethyl)-3-cephem-4-carboxylic acid 7-(3-benzylureido)-3-( l-methyll ,2,3-triazol-5- ylthiomethyl)-3-cephem-4-carboxylic acid 7-( 3-benzylureido)-3( 5 -methyl-] ,3,4-triazol-2- ylthiomethyl)-3-cephem-4-carboxylic acid 7-(3-benzylureido)-3-( l-methyl-l ,2,4-triazol-3- ylthiomethyl)-3-cephem-4-carboxylic acid 7-( 3-benzylureido)-3-( 1 -propyl-1 H-tetrazol-5 ylthiomethyl)-3-cephem-4-carboxylic acid 7-( 3-benzylureido)-3-( l-methyll ,2,4-triazol-3- ylthiomethyl)-3-cephem-4carboxylic acid EXAMPLE 36 To a 6.888 g aliquot of 7-amino-3-(2-methyl-l,3,4- thiadiazol-5-ythiomethyl) 3-cephem 4-carboxylic acid in a one litre reaction flask are added pyridine (500 ml), triethylamine (5.6 ml) and ethylisothiocyanate (3.5 ml). The mixture is heated with stirring at C for 3 hrs. The solvent is then removed by evaporation under reduced pressure and the residue is taken-up in acetic acid (20 ml) and ethyl acetate (250 ml).

After filtration, ethyl ether is added to precipitate 7- (3-ethylthioureido)-3-( 2-methyl-l ,3,4-thiadiazol-5- ylthiomethyl)-3-cephem-4-carboxylic acid.

R, 0.56 (i 0.10) in the system acetonitrile/methanol/water 6/3/1. UV. detection.

EXAMPLE 37 To a cold solution (0 C) of 7-amino-3-(2-methyll,3,4-thiadiazol-5-ylthiomethyl )-3-cephem-4- carboxylic acid (6.888 g) in 80 ml. of methylene chloride is added trichlorsilane. The medium is stirred for 15 minutes at 20 C and 100 ml. of toluene is added. The solution is cooled up to C and triethylamine (28 ml) and liquid C) phosgene (3.2 ml) are added. The medium is stirred for 3 hrs at -50 C. Most of the solvents is then eliminated under reduced pressure (1 mm Hg), the residual solution is allowed to reach room temperature and then immediately added to allylamine (0.888 ml) in methylene chloride (20 ml) with stirring for 10 hrs. After hydrolysis of the trimethylsilylester with water, the solvent is removed by evaporation and the residue is purified by chromatography on Silicagel Merck 0.2-0.06 mm to yield 7- (3-allylureido)-3-( 2-methyl-l ,3,4-thiadiazol-5- ylthiomethyl)-3-cephem-4-carboxylic acid with the same characteristics as the produce obtained in Example 15.

EXAMPLE 38 A mixture of 7-ACA (6.8 g), pyridine (500 ml) and allylisocyanate (3.3 ml) is heated to 50 C for 1 hour. The solvent is removed by evaporation under reduced pressure and the residue is taken up with acetic acid (20 ml) and ethylacetate (250 ml). By addition of ether, 7-(3-allylureido)-cephalosporanic acid is obtained. (R;= 0.25 (i 0.10) in the system methylisobutylketone/methanol/formic acid 60/6/2, detection with bromcresol green and KMnO To a cool mixture of water (15 ml) and acetone (15 ml) is added a 5.31 g aliquot of the above obtained compound and, by small fractions, 26.7 ml of N NaH- CO and, thereafter, a mixture of 4.8 ml of 0.2 M Natl-l P0 and 25.2 ml of 0.2 M Na HPO To the obtained solution, there is added a solution of 3.18 g of mercapto-2-methyl-1,3,4-thiadiazole in 12 ml. of acetone and 18 ml. of N NaHCO The mixture is heated with stirring up to 70 C for 3 hrs. The solution is cooled, filtered on charcoal and acidified to pH 1 with 12 N HCl. The solution is clarified by addition of acetone, filtered on charcoal and the acetone is eliminated by evaporation under reduced pressure. The gummy residue is separated from the supernatant and taken up in a minimum of methanol. The obtained precipitate is filtered to yield 7-(3- allylureido)-3-(2-methy1-1 ,3 ,4-thiadiazol-5 ylthiomethyl)-3-cephem-4-carboxylic acid with the same characteristics as the product obtained in Example l5.

EXAMPLE 39 To a suspension of 7-ACA (5.45 g) in methylene chloride (50 ml) at 0 C under dried-nitrogen, there is added at 0 C triethylamine (7 ml) and trimethylchlorsilane (6.4 ml) and the medium is allowed to react at that temperature for 15 minutes and then brought to room temperature. Toluene (40 ml) is added and the solution is cooled up to 70 C. Triethylamine (2.8 ml) and liquid phosgene (3.2 ml) at 70 C are added. The medium is allowed to react at 50 for 3 grs with stirring.

After filtration, most of the solvent is evaporated under reduced pressure (1 mm Hg) and the residual solution of trimethylsilyl-7-(isocyanato)- cephalosporanate is allowed to reach room temperature.

An aliquot of this solution containing 3.7 g. of trimethylsilyl-7-(isocyanato)cephalosporanate is added to a solution of 0.9 ml. of allylamine in 50 ml. of methylenechloride. After a 10 hrs reaction period, the trimethylsilyl ester is hydrolized with water, the solvents are evaporated and the residue is purified by chromatography on Silicagel (Merck 0.06-0.2 mm), 7-(3- ally1ureido)-3-(2-methyl-l ,3 ,4-thiadiazol-5- ylthiomethyl)-3-cephem-4-carboxylic acid with the same characteristics as the product obtained in Example is obtained.

EXAMPLE 40 To a solution of 2-thenylamine (2.26 g) in methylenechloride is added slowly trimethylsilyl-7- (isocyanato)-cephalosporanate (3.7 g) obtained as indicated in the first paragraph of Example 39. The medium is stirred for 1 hour, the ester is then hydrolized with water. The solvents are eliminated under reduced pressure and the residue is purified by chromatography on Silicagel (Merck 0.06-0.2 mm) to obtain 7-[3-(2- thenyl)-ureido]cephalosporanic acid.

To a solution of 7-[3-( 2-theny1)-ureido]-cephalosporanic acid (1.64 g) in 15 ml. ofa A acetone/water mixture and 10 ml. of 0.6 M NaHCO;,, there is added 2- mercapto-S-methyl-l ,3,4-thiadiazole (0.8 g) in acetone ml). After a 4 hrs reaction period at 65-70 C, the

.solution is cooled and acidified to pH 3.7 with 12 N HCl. The obtained precipitate is filtered and dried to yield 7-[3(2-theny1)-ureido] -3-(2-methy1-1 ,3 ,4- thiadiazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid.

nmr 2.68 s 3H),"3.39 d'(1H) (J 16 c./sec.), 3.71 d

4.5 c./sec.), 5.63 d (1H) (J 4.5 c./sec.), 7.05 d (2H) (J 3 c./sec.), 7.46 t (11-1) (J 3 c./sec.).

Using the same procedure, the following cephalosporins are obtained 7- [3 -(2-thenyl)-ureido]--3 -(1-methyl- 1 H-tetrazol-S- ylthiomethyl)-3-cephem-4-carboxylic acid nmr 3.44 d (1H) (J-ll c./sec.), 3.70 d (1H) (J 11 c./sec.), 3.94 s (31-1), 4.39 m (21-1 2H), 4.99 d (1H) (J 5 c./sec.), 5.60 d(1l-1) (J 5 c./sec.), 7.03 d (21-1) (J 3.3 c./sec.), 7.44 t (1H) (J 3.3 c./sec.).

7-(3 -furfurylureido)-3 (2-methyl- 1 ,3 ,4-thiadiazo1-5 ylthiomethyl)-3-cephem-4-carboxylic acid nmr 2.69 s (31-1), 3.53 d (1H) (J 18.6 c./sec.), 3.88 d (1H) (J 18.6 c./sec.), 4.20 d (11-1) (J 13 c./sec.), 4.28 s (21-1), 4.59 d 11-1) (J 13 c./sec.), 5.13 d (11-1) (J 5 c./sec.), 5.75 d (1H) (J 5 c./sec.), 6.28 d (1H) (J 3.4 c./sec.), 6.34 dd (1H) (J 3.4 c./sec. and 1.3 c./se'c.), 7.64 d (1H) (J 1.3 c./sec.).

EXAMPLE 41 In a one litre reaction flask and to a 6.888 g. aliquot of 7-amino-3-(2-methyl-1,3 ,4-thiadiazol-5- ylthiomethyl)-3-cephem-4-carboxylic acid prepared according to the procedure described in Example 1, are added pyridine (500 ml) and phenethylisocyanate (5.9 ml). The mixture is stirred for 2 hrs. at room temperature. The solvent is then removed by evaporation under reduced pressure at a temperature inferior to 40 C and the residue is taken up in acetic acid 20 ml) and ethyl acetate (250 ml).

After filtration, the solvent is removed by evaporation under reduced pressure. The residue is taken up in methanol ml) and by addition of ethyl ether (2.1) 7-(3-phenethylureido)l-(2-methyl-1,3 ,4-thiadiazol-5- ylthiomethyl)-3-cephem-4-carboxylic acid is obtained.

nmr 2.5-2.8 m s (2H 3H), 3.2-3.5 m (2H),

4.1-4.4 m (2H), 5.20-5.35 (11-1), 5.59 d (11-1) (J 4.0 c./sec.), 7.13 s(51'-l).-

Using the same procedure, the following cephalosporins are obtained:

7-(3 -phenethylureido)-3 (2-methyl- 1 ,3 ,4-triazol-5- ylthiomethyl)-3-cephem-4-carboxylic acid nmr 2.66 s (3H), 2.8 m (2H), 3.3 m (21-1), 3.39 d (1H) (J 17 c./sec.), 3.80 d(1I-1) (J 17 c./sec.), 4.5 m(2l-1), 5.03 d(11-1) (J 5.0 c./sec.), 5.68 d (11-1) (J 5.0 c./sec.), 7.28 s (5H).

7-93-phenethylureido)-3(pyrimidin-2- ylthiomethyl )-3-cephem-4-carboxylic acid nmr 2.78 t(21-1) (J 7.9 c./sec.), 3.15-3.45 m (21-1), 3.37 d (1H) (j 16.7 c./sec.),'3.77 d (11-1) (J 16.7 c./s ec.), 4.25 d (1H) (J 14 c./sec.), 4.67 d (1H) (J 14 c./sec.), 5.05 d 11-1) (J 5.2 c./sec.), 5.72 d(111) (J 5.2 c./sec.), 7.17 t (1H) (J 5.0 c./sec.), 7.27 s (51-1), 8.67 d(21-1)(J 5.0 c./sec.).

7-( 3p-chlorophenethylureido)-3-( 2-methyl-l ,3 ,4

.thiadiazol-Sylthiomethyl)-3-cephem-4-carboxylic acid nmr: 2.69 s (31-1), 2.70 m (2H) (J 6.35 c./sec.), 3.20

t (21-1) (J 6.35 c./sec.), 3.72 m(21-1), 4.22 d(l1-1) (J 13.3 c./sec.), 4.57 d (ll-1) (J 13.3 c./sec.), 5.10 d (1H) (J 5 c./sec.), 5.70 d (1 H) (J 5 c./sec.), 7.36 s (4H).

7-(3 pChlorophenethylureido)3(2-methyl-1 ,2,4-

I oxadiazol-5-ylthiomethyl )-3-cephem-4-carboxylic acid I (J 13.3 c./sec.), 5.09 d (1H) (J 5 c./sec.), 5.72 d ylthio groups; (1H) (J 5 c./sec.), 7.35 s (4H). R is a 5 or 6-membered heterocyclic group contain- -pp y d0)-3-( y ing carbon and one or more N. O, or S atoms, said i y P y group being unsubstituted or substituted with one acld or two lower alkyl groups of 1 to 4 carbon atoms; nmr 2.70 t (2H) (J 6.5 c./sec.), 3.30 t (2H) (J 6.5 and c./sec.), 3.72 m (2H), 3.95 s (3H), 4.20 d (1H) (J 13 c./sec.), 4.42 d (1H) (J 13 c./sec.), 5.08 d (1H) (J 5 c./sec.), 5.69 d (1H) (J 5 c./sec.), 7.32 s (4H). We claim: l. A compound of the formula:

M is hydrogen or an alkali metal cation.

2. A compound according to claim 1, where R is unsubstituted benzyl.

3. A compound according to claim 1, where R is 1 ,3 ,4-thiadiaZol-5-yl, 1 ,3 ,4-oXadiazol-5-yl, 1H- tetrazol-S-yl, l,2,4'-triazol-3-yl, or 1,2,3-triazol-5-yl, or a methyl derivative of any of such groups.

i S 15 4. A compound according to claim 1, being 7-(3- I benzylureido)-3-(S-methyl-1 ,3,4-thiadiaz0l-2- L... N CHZSR, ylthiomethyl)-3-cephem-4:carboxylic acid. O l 5. A compound according to claim 1, being 7-(3- COOM benzylureido)-3'(1-mety1-lH-tetrazol-5-ylthiomethyl)- 3-cephem4-carboxylic acid. wherein 6. A compound according to claim 1, being 7-(3- R is benzyl, said benzyl being unsubstituted or suby u d -y u0 y stituted with one or two halogen, hydroxy, mecephem-4-carboxylic acid. thoxy, methyl, nitro, acetamido, amino or meth- I Page 1 of 2 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION d PATENT NO. I 3,912,728

DATED October 14, 1975 INVENTOR(S) Pierre Crooij and Alain Colinet It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 38, change -d-- to "as" Column 4, line 39, change --H)-- to "antibacterials" 8 Column 5, line 1, change ---3-5-methyl--- to "3-(5-methyl" Column 12, line 15, change ---(J 51 c./sec.)--- to (J 5 c./sec.)

Column 16, line 52, change ---500 a--- to "5.00 d" a Column 17, line 65, change --(ld-- to "(l H)" Column 19, line 55, change -idhclorobenzyl)-- to "dichlorobenzyl)" Q Column 20, line 55, delete ---ml)- at end of sentence and add Column 23, line 19, change 3l [2-methyl--- to "-3- [2-methyl" 3 Column 23, line 65, change ]l3-2 to "]-3-[2-" Column 25, line 9, change (4methypyrid-- to (4-methyl pyrid" Column 25, line 17, change -heterocyclucthiomethylto "heterocyclicthiomethyl" Page 2 of 2 UNITED STATES PATENT OFFICE C'HFICATE 0F COREQTIQN O PATENT NO. 1 3,912,728

DATED October 14, 1975 INVENTOR(S) Pierre Crooij and Alain Colinet It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below: 0 a

Column 25, line 47 and 48, change --7-(3benzylureido)-benzylureido)-3(s-triazin-Z-ylthiomethyl)3- to "7-(3-benzylureido)3(4+methylstriazin-2-ylthiomethyl)3" Column 26, line 51, change --produce-- to "product" a 7 Column 27, line 26, change -3 grs to "3 hrs" Column 28, line 34, change l- (2-methylto 3- (2-methyl" Column 28, line 47, change -793-- to "7-(3-" Q 7 Column 28, line 64, change (2-methyll,2,4 to (2-methyl- 1,3y4

Column 30, line 22, change --2-ylthuomethylto "2-ylthiomethyl" Q I I lgncd and Seated thus Twentieth Day Of July 1976 [SEAL] a Arrest.

RUTH. C. MASON C. MARSHALL DANN Office Commissioner nj'Parents and Trademarks 

1. A COMPOUND OF THEFORMULA:
 2. A compound aCcording to claim 1, where R1 is unsubstituted benzyl.
 3. A compound according to claim 1, where R2 is 1,3,4-thiadiazol15-yl, 1,3,4-oxadiazol-5-yl, 1H-tetrazol-5-yl, 1,2,4-triazol-3-yl, or 1,2,3-triazol-5-yl, or a methyl derivative of any of such groups.
 4. A compound according to claim 1, being 7-(3-benzylureido)-3-(5-methyl-1,3,4-thiadiazol-2-ylthiomethyl)-3-cephem-4 -carboxylic acid.
 5. A compound according to claim 1, being 7-(3-benzylureido)-3-(1-metyl-1H-tetrazol-5-ylthiomethyl)-3-cephem-4 -carboxylic acid.
 6. A compound according to claim 1, being 7-(3-benzylureido)-3-(1,3,4-triazol-2-ylthuomethyl)-3-cephem-4-carboxylic acid. 